libavcodec/fft.h File Reference

#include <stdint.h>
#include "config.h"
#include "libavutil/mem.h"
#include "avfft.h"

Go to the source code of this file.

Data Structures
struct	FFTContext
struct	RDFTContext
struct	DCTContext
Defines
#define	FF_MDCT_PERM_NONE   0
#define	FF_MDCT_PERM_INTERLEAVE   1
#define	COSTABLE_CONST
#define	SINTABLE_CONST
#define	SINETABLE_CONST
#define	COSTABLE(size)   COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
#define	SINTABLE(size)   SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
#define	SINETABLE(size)   SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]
Functions
	COSTABLE (16)
	COSTABLE (32)
	COSTABLE (64)
	COSTABLE (128)
	COSTABLE (256)
	COSTABLE (512)
	COSTABLE (1024)
	COSTABLE (2048)
	COSTABLE (4096)
	COSTABLE (8192)
	COSTABLE (16384)
	COSTABLE (32768)
	COSTABLE (65536)
void	ff_init_ff_cos_tabs (int index)
	Initializes the cosine table in ff_cos_tabs[index].
	SINTABLE (16)
	SINTABLE (32)
	SINTABLE (64)
	SINTABLE (128)
	SINTABLE (256)
	SINTABLE (512)
	SINTABLE (1024)
	SINTABLE (2048)
	SINTABLE (4096)
	SINTABLE (8192)
	SINTABLE (16384)
	SINTABLE (32768)
	SINTABLE (65536)
int	ff_fft_init (FFTContext *s, int nbits, int inverse)
	Sets up a complex FFT.
void	ff_fft_permute_c (FFTContext *s, FFTComplex *z)
void	ff_fft_calc_c (FFTContext *s, FFTComplex *z)
void	ff_fft_init_altivec (FFTContext *s)
void	ff_fft_init_mmx (FFTContext *s)
void	ff_fft_init_arm (FFTContext *s)
static void	ff_fft_permute (FFTContext *s, FFTComplex *z)
	Do the permutation needed BEFORE calling ff_fft_calc().
static void	ff_fft_calc (FFTContext *s, FFTComplex *z)
	Do a complex FFT with the parameters defined in ff_fft_init().
void	ff_fft_end (FFTContext *s)
static void	ff_imdct_calc (FFTContext *s, FFTSample *output, const FFTSample *input)
static void	ff_imdct_half (FFTContext *s, FFTSample *output, const FFTSample *input)
static void	ff_mdct_calc (FFTContext *s, FFTSample *output, const FFTSample *input)
void	ff_kbd_window_init (float *window, float alpha, int n)
	Generate a Kaiser-Bessel Derived Window.
void	ff_sine_window_init (float *window, int n)
	Generate a sine window.
void	ff_init_ff_sine_windows (int index)
	initialize the specified entry of ff_sine_windows
	SINETABLE (32)
	SINETABLE (64)
	SINETABLE (128)
	SINETABLE (256)
	SINETABLE (512)
	SINETABLE (1024)
	SINETABLE (2048)
	SINETABLE (4096)
int	ff_mdct_init (FFTContext *s, int nbits, int inverse, double scale)
	init MDCT or IMDCT computation.
void	ff_imdct_calc_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute inverse MDCT of size N = 2^nbits.
void	ff_imdct_half_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute the middle half of the inverse MDCT of size N = 2^nbits, thus excluding the parts that can be derived by symmetry.
void	ff_mdct_calc_c (FFTContext *s, FFTSample *output, const FFTSample *input)
	Compute MDCT of size N = 2^nbits.
void	ff_mdct_end (FFTContext *s)
int	ff_rdft_init (RDFTContext *s, int nbits, enum RDFTransformType trans)
	Sets up a real FFT.
void	ff_rdft_end (RDFTContext *s)
void	ff_rdft_init_arm (RDFTContext *s)
static av_always_inline void	ff_rdft_calc (RDFTContext *s, FFTSample *data)
int	ff_dct_init (DCTContext *s, int nbits, enum DCTTransformType type)
	Sets up DCT.
void	ff_dct_calc (DCTContext *s, FFTSample *data)
void	ff_dct_end (DCTContext *s)
Variables
COSTABLE_CONST FFTSample *const	ff_cos_tabs [17]
SINETABLE_CONST float *const	ff_sine_windows [13]

---

Define Documentation

#define COSTABLE

(

size

)

COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]

Definition at line 65 of file fft.h.

#define COSTABLE_CONST

Definition at line 60 of file fft.h.

#define FF_MDCT_PERM_INTERLEAVE   1

Definition at line 52 of file fft.h.

Referenced by ff_fft_init_arm(), and ff_mdct_init().

#define FF_MDCT_PERM_NONE   0

Definition at line 51 of file fft.h.

Referenced by ff_mdct_init().

#define SINETABLE

(

size

)

SINETABLE_CONST DECLARE_ALIGNED(16, float, ff_sine_##size)[size]

Definition at line 69 of file fft.h.

#define SINETABLE_CONST

Definition at line 62 of file fft.h.

#define SINTABLE

(

size

)

SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]

Definition at line 67 of file fft.h.

#define SINTABLE_CONST

Definition at line 61 of file fft.h.

---

Function Documentation

COSTABLE

(

65536

)

COSTABLE

(

32768

)

COSTABLE

(

16384

)

COSTABLE

(

8192

)

COSTABLE

(

4096

)

COSTABLE

(

2048

)

COSTABLE

(

1024

)

COSTABLE

(

512

)

COSTABLE

(

256

)

COSTABLE

(

128

)

COSTABLE

(

64

)

COSTABLE

(

32

)

COSTABLE

(

16

)

void ff_dct_calc	(	DCTContext *	s,
		FFTSample *	data
	)

Definition at line 170 of file dct.c.

Referenced by calc_input_response(), decode_block(), and main().

void ff_dct_end

(

DCTContext *

s

)

Definition at line 206 of file dct.c.

Referenced by decode_end(), main(), and wmavoice_decode_end().

int ff_dct_init	(	DCTContext *	s,
		int	nbits,
		enum DCTTransformType	type
	)

Sets up DCT.

Parameters:

nbits

size of the input array: (1 << nbits) for DCT-II, DCT-III and DST-I (1 << nbits) + 1 for DCT-I

Note:

the first element of the input of DST-I is ignored

Definition at line 175 of file dct.c.

Referenced by decode_init(), main(), and wmavoice_decode_init().

static void ff_fft_calc	(	FFTContext *	s,
		FFTComplex *	z
	)			[inline, static]

Do a complex FFT with the parameters defined in ff_fft_init().

The input data must be permuted before. No 1.0/sqrt(n) normalization is done.

Definition at line 130 of file fft.h.

Referenced by ff_imdct_half_c(), ff_mdct_calc_c(), ff_rdft_calc_c(), imc_imdct256(), and main().

void ff_fft_calc_c	(	FFTContext *	s,
		FFTComplex *	z
	)

Definition at line 364 of file fft.c.

Referenced by ff_fft_init().

void ff_fft_end

(

FFTContext *

s

)

Definition at line 203 of file fft.c.

Referenced by av_fft_end(), ff_mdct_end(), ff_rdft_end(), imc_decode_close(), and main().

int ff_fft_init	(	FFTContext *	s,
		int	nbits,
		int	inverse
	)

Sets up a complex FFT.

Parameters:

	nbits	log2 of the length of the input array
	inverse	if 0 perform the forward transform, if 1 perform the inverse

Definition at line 81 of file fft.c.

Referenced by av_fft_init(), ff_mdct_init(), ff_rdft_init(), imc_decode_init(), and main().

void ff_fft_init_altivec

(

FFTContext *

s

)

Definition at line 139 of file fft_altivec.c.

Referenced by ff_fft_init().

void ff_fft_init_arm

(

FFTContext *

s

)

Definition at line 39 of file fft_init_arm.c.

Referenced by ff_fft_init().

void ff_fft_init_mmx

(

FFTContext *

s

)

Definition at line 22 of file fft.c.

Referenced by ff_fft_init().

static void ff_fft_permute	(	FFTContext *	s,
		FFTComplex *	z
	)			[inline, static]

Do the permutation needed BEFORE calling ff_fft_calc().

Definition at line 122 of file fft.h.

Referenced by ff_rdft_calc_c(), imc_imdct256(), and main().

void ff_fft_permute_c	(	FFTContext *	s,
		FFTComplex *	z
	)

Definition at line 178 of file fft.c.

Referenced by ff_fft_init().

static void ff_imdct_calc	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)			[inline, static]

Definition at line 138 of file fft.h.

Referenced by IMLT(), imlt_gain(), main(), nelly_decode_block(), and wma_decode_block().

void ff_imdct_calc_c	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)

Compute inverse MDCT of size N = 2^nbits.

Parameters:

	output	N samples
	input	N/2 samples

Definition at line 166 of file mdct.c.

Referenced by ff_fft_init().

static void ff_imdct_half	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)			[inline, static]

Definition at line 142 of file fft.h.

Referenced by at1_imdct(), decode_subframe(), do_imdct(), imdct_and_window(), imdct_and_windowing(), sbr_qmf_analysis(), sbr_qmf_synthesis(), synth_filter_float(), and vorbis_parse_audio_packet().

void ff_imdct_half_c	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)

Compute the middle half of the inverse MDCT of size N = 2^nbits, thus excluding the parts that can be derived by symmetry.

Parameters:

	output	N/2 samples
	input	N/2 samples

Definition at line 124 of file mdct.c.

Referenced by ff_fft_init(), and ff_imdct_calc_c().

void ff_init_ff_cos_tabs

(

int

index

)

Initializes the cosine table in ff_cos_tabs[index].

Parameters:

index

index in ff_cos_tabs array of the table to initialize

Definition at line 67 of file fft.c.

Referenced by ff_dct_init(), ff_fft_init(), and ff_rdft_init().

void ff_init_ff_sine_windows

(

int

index

)

initialize the specified entry of ff_sine_windows

Definition at line 55 of file mdct_tablegen.h.

Referenced by aac_decode_init(), aac_encode_init(), atrac1_decode_init(), decode_init(), ff_wma_init(), init_mdct_win(), and main().

void ff_kbd_window_init	(	float *	window,
		float	alpha,
		int	n
	)

Generate a Kaiser-Bessel Derived Window.

Parameters:

	window	pointer to half window
	alpha	determines window shape
	n	size of half window

Definition at line 35 of file mdct.c.

Referenced by aac_decode_init(), aac_encode_init(), and ac3_decode_init().

static void ff_mdct_calc	(	FFTContext *	s,
		FFTSample *	output,
		const FFTSample *	input
	)			[inline, static]

Definition at line 147 of file fft.h.

Referenced by apply_mdct(), apply_window_and_mdct(), and main().

void ff_mdct_calc_c	(	FFTContext *	s,
		FFTSample *	out,
		const FFTSample *	input
	)

Compute MDCT of size N = 2^nbits.

Parameters:

	input	N samples
	out	N/2 samples

Definition at line 186 of file mdct.c.

Referenced by ff_fft_init().

void ff_mdct_end

(

FFTContext *

s

)

Definition at line 228 of file mdct.c.

Referenced by aac_decode_close(), aac_encode_end(), ac3_decode_end(), atrac1_decode_end(), cook_decode_close(), dca_decode_end(), decode_end(), encode_end(), ff_aac_sbr_ctx_close(), ff_mdct_init(), ff_wma_end(), main(), twin_decode_close(), vorbis_encode_close(), and vorbis_free().

int ff_mdct_init	(	FFTContext *	s,
		int	nbits,
		int	inverse,
		double	scale
	)

init MDCT or IMDCT computation.

Definition at line 61 of file mdct.c.

Referenced by aac_decode_init(), aac_encode_init(), ac3_decode_init(), atrac1_decode_init(), create_vorbis_context(), dca_decode_init(), decode_init(), encode_init(), ff_aac_sbr_ctx_init(), init_atrac3_transforms(), init_cook_mlt(), init_mdct_win(), main(), vorbis_parse_id_hdr(), and wma_decode_init().

static av_always_inline void ff_rdft_calc	(	RDFTContext *	s,
		FFTSample *	data
	)			[static]

Definition at line 212 of file fft.h.

Referenced by calc_input_response(), decode_block(), ff_dct_calc_I_c(), ff_dct_calc_II_c(), ff_dct_calc_III_c(), ff_dst_calc_I_c(), main(), qdm2_calculate_fft(), and wiener_denoise().

void ff_rdft_end

(

RDFTContext *

s

)

Definition at line 130 of file rdft.c.

Referenced by decode_end(), ff_dct_end(), main(), qdm2_decode_close(), and wmavoice_decode_end().

int ff_rdft_init	(	RDFTContext *	s,
		int	nbits,
		enum RDFTransformType	trans
	)

Sets up a real FFT.

Parameters:

	nbits	log2 of the length of the input array
	trans	the type of transform

Definition at line 99 of file rdft.c.

Referenced by decode_init(), ff_dct_init(), main(), qdm2_decode_init(), and wmavoice_decode_init().

void ff_rdft_init_arm

(

RDFTContext *

s

)

Referenced by ff_rdft_init().

void ff_sine_window_init	(	float *	window,
		int	n
	)

Generate a sine window.

Parameters:

	window	pointer to half window
	n	size of half window

Definition at line 49 of file mdct_tablegen.h.

Referenced by encode_init(), ff_init_ff_sine_windows(), imc_decode_init(), init_cook_mlt(), and wmavoice_decode_init().

SINETABLE

(

4096

)

SINETABLE

(

2048

)

SINETABLE

(

1024

)

SINETABLE

(

512

)

SINETABLE

(

256

)

SINETABLE

(

128

)

SINETABLE

(

64

)

SINETABLE

(

32

)

SINTABLE

(

65536

)

SINTABLE

(

32768

)

SINTABLE

(

16384

)

SINTABLE

(

8192

)

SINTABLE

(

4096

)

SINTABLE

(

2048

)

SINTABLE

(

1024

)

SINTABLE

(

512

)

SINTABLE

(

256

)

SINTABLE

(

128

)

SINTABLE

(

64

)

SINTABLE

(

32

)

SINTABLE

(

16

)

---

Variable Documentation

COSTABLE_CONST FFTSample* const ff_cos_tabs[17]

Definition at line 50 of file fft.c.

Referenced by ff_dct_init(), ff_init_ff_cos_tabs(), and ff_rdft_init().

SINETABLE_CONST float* const ff_sine_windows[13]

Definition at line 42 of file mdct_tablegen.h.

Referenced by decode_init(), ff_init_ff_sine_windows(), ff_wma_init(), imdct_and_window(), and main().